package cn.tedu.v6;

import java.io.*;
import java.net.BindException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.*;


public class Server {
    private ServerSocket serverSocket;
    private static final  Integer PORT=6666;
    private List<PrintWriter> allOut=new ArrayList<>();
    //1.私有化集合保存所有用户名--onlineUsers
    private Map<String,String> userDataBase;
    private Set<String> onlineUsers=new HashSet<>();

    public Server() {
        try {
            serverSocket=new ServerSocket(PORT);

            userDataBase=new HashMap<>();
            userDataBase.put("海燕","123456");
            userDataBase.put("小燕","654321");
        } catch (BindException e){
            System.out.println("端口号重复申请，建议换个端口号");
        } catch (IOException e) {
            System.out.println("申请端口号失败....");
        }
    }

    public void start(){
        try {
            while(true) {
                System.out.println("----等待客户端链接-----");
                Socket socket = serverSocket.accept();

                new Thread(new ClientHandler(socket)).start();
            }
        } catch (IOException e) {
            System.out.println("服务器端通讯断开了");
        } finally {
            if(serverSocket!=null&&!serverSocket.isClosed()){
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    System.out.println("服务器关闭失败");
                }
            }
        }
    }

    public static void main(String[] args) {
        new Server().start();
    }
    private synchronized void broadcastMessage(String message){
        for(PrintWriter pw: allOut){
            pw.println("消息广播："+message);
        }
    }
    //2.封装方法：同步转发给所有客户端消息：“在线用户：”+username
    //updateOnlineUsers 更新在线人名单的方法：“在线用户：”+username
    //字符串：String userList=“在线用户：”+String.join（“、”，onlineUsers）

    private synchronized void updateOnlineUsers() {
        //构造在线用户列表字符串
        String userList = "在线用户：" + onlineUsers;
        //遍历所有在线集合，用顿号拼接
        for (String user : onlineUsers) {
            userList += user + "、";
        }
        //将在线用户列表广播给所有客户端
        broadcastMessage(userList);
    }
    private class ClientHandler implements Runnable{
        private Socket socket;
        private String ip;
        private BufferedReader br;
        private PrintWriter pw;
        private Socket ClientSocket;

        private String username;
        private String password;



        public ClientHandler(Socket s){
            this.socket=s;
            this.ClientSocket=s;
            ip=socket.getInetAddress().getHostAddress();
            try {
                br = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF8"));
                pw=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(),"UTF8")),true);
                synchronized (allOut) {
                    allOut.add(pw);
                }

            } catch (IOException e) {
                System.out.println("客户端断开通讯~~");
            }
        }

        private boolean Login(String user,String pass){

            return userDataBase.containsKey(user)&&userDataBase.get(user).equals(pass);
        }
        private void handlerChat(){
            new Thread(()->{
                try {
                    String message;
                    while((message=br.readLine())!=null){
                        System.out.println("客户端说："+message);
                        System.out.println("服务器请输入：");
                        broadcastMessage(message);
                    }
                } catch (IOException e) {
                    System.out.println("客户端读入失败！");
                }
            }).start();
            Scanner input =new Scanner(System.in);
            while (true) {
                System.out.println("服务器端请输入：");
                String  say=input.nextLine();
                //如果服务器端输入exit（不考虑大小写），就退出聊天
                if(say.equalsIgnoreCase("exit")){
                    System.out.println(username+"客户端断开连接，ip是："+ip);
                    pw.println(username+"退出聊天室");
                    System.out.println("拜拜");
                    System.exit(0);
                }else{    //如果不是exit，就发送给客户端
                    pw.println(say);
                }
            }
        }

        public void run() {
            try{
                pw.println("请输入用户名:");
                username = br.readLine();
                pw.println("请输入密码:");
                password = br.readLine();
                if(Login(username,password)){
                    pw.println("登录成功，欢迎进入聊天室！");
                    System.out.println("登录成功，欢迎进入聊天室！");
                    //3.所有用户添加至集合中【同步】
                    //添加用户到在线用户集合中
                    onlineUsers.add(username);
                    //更新在线用户列表
                    updateOnlineUsers();

                    handlerChat();
                }else{
                    pw.println("登录失败，用户名或者密码错误");
                    socket.close();
                }


            }catch(IOException e){
                System.out.println("服务器断开连接");
            }
            catch(NullPointerException e){
                System.out.println("IO流传入对象，有对象为null，立马核对，建议查看try块对象可能没赋值");
            } finally {
                //4.客户端断开链接，移除当前集合【同步】
                synchronized (allOut) {
                    allOut.remove(pw);
                }


                if(br!=null)
                    try {
                        br.close();
                    } catch (IOException e) {
                        System.out.println("结束通讯，关闭失败");
                    }
                if(pw!=null)
                    pw.close();

                if (socket!=null&&!socket.isClosed())
                    try {
                        socket.close();
                    } catch (IOException e) {
                        System.out.println("通讯关闭失败");
                    }

            }
        }
    }


}


